Percussion fuse



April 14, 1925.

(3. P. WATSON PERCUSSION FUSE Filed Aug. 27, 1923 K @Hernani Patented Apr. 14, 1925.

CHARLES ,1w wie@ 0F 2913K, ,PENNSYLVANIA PERCUSSION FUSE.

Application filed August 2`7`,1l23.4 tSerial No. 659,523.v

To all whom it may Concern.'

Be it `known that l, CHARLES?. WATSON, a citizen ot' .the United States', .residing at York, in .the eounty of York vandjtate of Peiuisylvania, have invented .,cel'fei11-nQW and useful Improvements VAin' :Percussion Fu'ses, of Whih Vthe following i'S ,especiiiention. A 1

My invention relatesto .permission uSeS such s are used lin connect-ion with ordnance vprojectilegsoine.of the, novel ,features ot vwhich; howewer, areV adapted fornse in fuses used .orotlier purposes.

In my pendlngapplication tor Spatlhave illuetrated ,a percussion fuse ,having many features' in common 4 withthnt .which I 'illustrate and shall :herein describe. Sonie .of the leatuiesof noYelty that nitty be' Yillustrated in this esige, and which. 'illustrated in .my .zlfoljezifid application, 1re

11e.' also Clziilned in the hitter. I -v Referring `to the; aeeoinpanying )Adi-15V- ngls .Y Y

Figure l is. a CentrallQllgiLlClal 4SGC- tion. of a ,percussiondetongiting -nse @depted to he applied to a high explosiyeshll t tie Y Figure ,2 ,is adeentral longitudinal See- `tion of 4-thedtnsewthe parte being in ipnnied position.

Fig', 3 is .a ,traneiierse sec-tional View ,taken voir/the line llllll of Fig. 1f

' Fig, 4f is n detail face if'iew'zof the ping that ferries .the spinner.

Fie". is n ydetail facie View logt the metal 4lisltlmt is located .liet-.Ween theneaijrie'r for :the primernnd the carrier ifor thedetonetor,

land the felt cover therefor.

Fig. 6 y.iS @Vie- W similari@ ifl- 5 With.

the jpriiner plug also repijeeented,`

Fig? is ,a central llongitndmalsectional (view through n piiinerplngof different l`forni' i'onizthat illusgtrted in 1.and12, andthe Vcarrier for the detonator 4andthe ,immediately :issocizited parts.

ilig. S is n eentrnl,longitudinal lsectional view of a rdisk carrying' two vprimers -arranged ,in tandem.

I .F 9 is n central longitudinal Section Similar teilig. 7 but showing' still .another embodiment of vmy invention. y

Fig'. l0 is uvei'oss sectional :View taken on the linev 0f Fig. 9.

Fie 11..-i S, fr. central lenemdnel .Sectional siew .of .the Cannet for. .the .detenetel ,1.1.11- Hloaded drawn .to .a lnrgerseale thanthe .Otle'n 13W@ i i The detoneting .fuse repreented; in. the drawings. is .of @the type adapted; t0, be scirewed into` .the rear .of a plnjetle., and v.has e .body 2,; nlthe forward, and. 0f ,Wei-.Ch .formed helbel :for the bQQSter eharge and in* lthe'rear portion aeeeeond diambe 33,. in which. are located diesereral rfunpcltioningj lni eehenionl eleinexnts of the fuse. The two .Chambers yare conneotedsflgy 21 channel. .of ,eommuefetiom 3.4,. QlfnfiG/d through the .partition separating the chemvhere, wlliell. .Deseee AServes .as ,Channel 0f ,detonation between the vdetonntor V41 sind thebeestel..Charge The .ehember 3,3 .deepen Werd the rear but is iedenfedi9-1b@ .Clesd 'by slfewntlu'eedel Plug@ fermed with' il tiene@ @dented to @but against- .tl @ed .fof .the Steek 0r bQdyfQ.OihuS- l Hthin the. Chamber .33.1S leted 'the movable .lmmmer block -.thet .Ce/rues the firing-pin 13; #Thie harnrner block isl Lpef- .erebly gfezmed., Qi. el Cyli-.nfll elipiecff'f :metalihet fits thehambelx efly clesely, A,enduits `of a lerigtl-rleesv ntligir'rtht of 'the .chamber .Se that .it sile@ te met@ llngibudinellytherein@ the fue@ .fil.I.1.CL`OJ1,S.V lBetween the rezuj end of the hgnniner bloelegrnd `the elosing plng, and siezelY 'inmirfege ges, .and e6, formed thliefee lsi 0tvly..n ih@ .nlug @ed .hammer bll iS a? Geil ,Sii'ile' .3 ,the onnoit@ @11de Qf inlaid? er@ .fespectzf'ly eonneeted with .thesgiid parte. pon- .neetions are vconveniently.formed ,by internally sjcyreiv-.threeding ythe 4apertures -lfiiinl 46, is indieated it 47, iind'fczineiniif the. ekgils oi? `the .Spring 3 engage .with lsnid'itlneade7 hy a kScreyvling notion. "The elipring is Qon- I tracztile in its-tendency .and serves .to hold 'tliedplunger o1 haiiirner Qhl'oel, A preventing ltfomverfl ereeping thereof during bflight of thel projectile. -'[t .will :he linderstood :that the `Sizgijilig is not Strong' enoiigh .to Qifeiiahy "enbjstzintiall opfpo,Sitioni tothe foiwai'cl`vinoienient lof the hainin'er `block when vvthe .projecy vtile stniliesA theV target-gf jund ivhenthisl oecnrs .the block will nioije forward,V cerrying the :firing pin .intofnnetiQningi'engagement with :the: primeilof the fnseoniisjng .the fixing .of

- extending beyond the front face of the hammer block. Vhen the fuse is unarmed, the

firing pin being turned to the position represented in Fig. 1, its point is then entirely within the slot or recess and therefore so shielded that it cannot under any conditions act upon the primer of the fuse. Seated in an eccentric aperture 11 in the hammer block is a pin or freely moving plunger 24 acted upon by a spring 25 that tends to move it inwardly. The end of this pin is adapted to enter a recess 4 formed in the eccentric portion 16 of the firing pin and thus hol-d the latter locked in unarmed position. A removable sleeve S) surrounds the forward portion of the hammer block and serves to maintain the pivot pin 12, the plunger 24 and the spring 25 that 'acts on the latter, in pla-ce, this sleeve being slipped over the hammer block after the parts just referred to have been properly assembled. A second plunger pin 38 is supported in an aperture provided therefor in the hammer block parallel to the longitudinal axis thereof and is acted upon by a spring 39 that tends to move it in a forward direction. This pin, 38, bears against a face, 14, of the eccentric 16, when the firing pin occupies the safety position represented in Fig. l, and acts to 1 maintain the firing pin in this position against any tendency that might tend to move it into armed position, such as centrifugal force generated by the rotation of a shell carrying the fuse if it should for instance roll down an incline. The pin maintains this locking position until moved rearward against the action of its spring 39, as for instance when the plunger is violently set back at. the instant of firing the projectile .carrying the fuse from a gun.

The two plunger pins 24 and 38, movableV on lines which are at right angles to each other, and one adapted to be set back against the action of its spring when the shell is fired, and the other to be set back7 by'centrifugal force while the shell is in,A flight, serve to maintain the firing pin inA safety position under alll conditions to tained in its set back position while theY connected therewith in the safety position represented in Fig. 1, until acceleration of the shell ceases, because this force of inertia is more powerful during the period of violent acceleration than the centrifugal, and hence overcomes the latter. however, as the shell begins to rotate and centrifugal force is developed, the locking plunger pin 24 is moved to free the firing pin, which is turned into armed position As soon,

as soon as the centrifugal force acting on' part 16 becomes effective, as against the force of 4inertia acting thereon as just set forth, and this takes place shortly after the shell has left the muzzle of the gun.

This feature is very important as it in-' sures that the plunger is not armed while the fuseand loaded shell are in the bore of the gun. Premature explosions in the bore of the gun cannot therefore take place, due to any obstruction in the rifiing, to' which such premature explosions have been attributed.

Locking pin 38 has a little play in the aperture in which it is located, so that when the shell is in rotation it tends to hug the outer wall of its recess, -due to the action of centrifugal force, and the recess for this pin Vis so located that its outer edge lies a little outside of the inner edge of the sleeve 9. The result of this arrangement is that as soon as acceleration of the shell in its flight ceases, shortly after passing the muzzle of the gun, the spring 39 acts to advance the plunger or locking pin 38, but moves it only far enough to cause the end of the plunger to come into engagement with vthe edge of the sleeve 9, where it is held in a position that will not allow it to interfere with free movement-s of the firing pin. The engagement of the pin 38 with the edge of the sleeve is very slight, but is sufficient for the purpose stated, especially when held in such engagement by centrifugal force. At the instant the shell strikes armor plate or other target,'the resistance offered by the slight engagement of the pin 38 with the edge of the sleeve is overcome and the pin moves forward to its fullest extent and lies outside of a face 15 of the eccentric portion of the firing pin, in which position it operates to positively hold the pin so that it there is an igniting passage 28 communicating with the cavity 27 for the detonator. A central axial opening 38, much larger in diameter than the igniting passage 28 and preferably co-axial therewith, is formed in the hub portion 49 of the plug 21, leading from the rear face of the latter to the diametric hole 23. Into this larger axial opening is inserted a tightly fitting plug or closing piece 26, the wall of the'opening being preferably screw-threaded to receive such plug. A. delay powder train 42 is located in the hole or transverse passage 23. The passage preferably opens at each end into the space 22, so that the powder train 42 is ignited from each end and thus in effect becomes two trains whichappro-ach each other at the axial center of the detonator plug. These trains consist each of a mass of compressed black or other relatively slow burning powder that fills the hole 23 from one open end thereof to about where the closing plug 26 is seated. The central portion of the hole 23 is filled with and constitutes a lnagazine for a small charge of loose line grain igniting powder, 42a. This magazine may be conveniently loaded through the central axial opening, after which the closing plug 26 is applied. The inner walls of the hole 23 are preferably screw-threaded, and the powder train, being compressed therein, lills the grooves between the threads, and thus there is formed an easy and convenient means for effectively preventing fiame or hot gases from creeping along the outside of the delay train in advance of the complete burning thereof, as has been found to sometimes occur when the powder train is loaded into a small passage having smooth walls.

A thin disk or plate 31, preferably of metal, lies between the primer plug 18 and the detonator plug 21, the diameter of this disk being practicallythe same as that of the plug 2l. Its edge is notched, as indicated at 35, and to one of its faces is secured a washer 32 of felt or similar yielding material. In assembling the parts of the fuse the washer 32 is placed next the inner end of the hub of the plug 21. It serves the double purpose of a cushion between the screw or primer plug and the detonator plug` and also as a seal against the passage of llame from the igniting passage 22 to the axial opening into which is set the plug 26. lhile the latter plug is intended to make the axial opening gas tight, it is possible that under the great strains that obtain upon impact of a shell the flame from the primer might reach the magazine of igniting powder, 42a, through thev axial opening in the hub 49, and thus cause firing of the detonator without reference to the action of the delay train. y

The use of the two powder time trains not only provides greater certainty in the ignition than if one only were used-but'when both are ignited simultaneously and burn toward each other the resulting subsequent ignition effect is greatly increased when both burn out at the same instant. In such case the magazine of loose igniting powder may be dispensed with. It is practicable to use one, or more powder trains,-and the greater the number the more certain the ignition thereof, and the greater the resulting igniting effect under favorable conditions.

The number o-f notches 35 in the 'edge of the disk 31 differs from the number of igniting passages 2O and these two are respectively so arranged that the parts 1S and 31 cannot be properly assembled without one or more of the flash passages communicating with one or more of the notches 35, with the result that there is always a. communication between the primer recess and the peripheral flash passage 22, so that when the primer is fired the llame therefrom is communicated to the opposite ends of the delay train, but through tortuous passages; which is of advantage, as better results are obtained in igniting a delay powder train if the intense blast of flame from the primer is not communicated directly to the end of the powder train to be ignited, but rather in an indirect manner, as through a tortuous passage such as described. By having' two delay trains with two ends therefore that may be ignited, I reduce the danger of failure to lire the magazine of igniting powder. Each compressed powder train is formed to give the delay, say one-tenth of a second, that is desired in the functioning of the fuse upon impact.

36 designates a shield or protecting cap covering a portion of the forward end of the plug for the detonator, which end is preferably curved or dome-shaped to it the face of the partition wall 44 that is toward the cavity 33. This shield is preferably formed of thin metal and serves to maintain the detonator' in its cavity 27 and protect it againstV the set forward on impact of the shell. The shield is crimped at its circumference into a corresponding groove cut in the detonator plug so that it acts as a gas check. Under said shield 36 is preferably placed a disk 51 of water-proof paper.

Under certain conditions it may be found necessary to make the metal shield thicker, at the middle than the edge, and of lens shape so that it serves to refract the detonating waves arising from the explosion of the detonator.

In Fig. 7 I illustrate another and somewhat more simple form of plug for the det-- onator dela-y train of the fuse.- In this form of the invention the delay train or pellet is located in an open recess 23 formed in the rear face of the cylindrical piece 21,-.-

instead ot in a passage like that designated 23, closed except at its ends. The open cavity 22:3 is covered and `closed by the felt washer 32 carried by the plate Y3l. lt is connected at one endV with the base of the detonator cavity 27, by an igni-ting 'passage 5t), and at the other end with the circu1nfercntial ilash or igniting' passage 22. rThis latter tormot carrier plug t'or the detonator and delay train is easier to malle than those shown in other designs and has the advantage of giving a more uniform time of burning, though lthe possibility of shorteircuiting is greater, when the assembling is not properly done. I have shown this particular design in duplicate to insure the i'gnitionrof the delay teature'of the fuse.

It is also practicable, as Arepresented in Figs. 9 and lO to dispense entirely with the central axial opening' with its closing plug 2G and yet retain the yadvantages incident to that construction. In this case au ctfcenter hole 6() is drilled through the hub -lot' the plug. the atial center of which is a'chord through the hub. Another hole Gl passes through the smaller segment of the hub produced by the hole 60, and communiates at right angleswith the hole 60 at yits center. The hole GO'communicates withthe igniting passage 2S through a small passage 62. i

In using this form ot the invention the hole GO is loaded from end to end with black or other slow burningpowder compressed to a considerable degree. A proper tool isthen Vpassed through the-hole Gl and'c-uts out the central portion of the powder train in hole GO, forming two delay powdertrains whoseexp'oscd ends are respectively at the opposite sides ofthe hub 49. A loose char-ge ot' tine grain black powder to constitute the magazine ot igniting powder isr then introduced into lthe space between the ends ofthe compressed*delay powder trains in the hole GO. and is'tliere confined by a plug 63 which is tightly fitted into the'hole 6l.

There a number otpractical advantages incident to carrying botlrthei detonator and the delay ortime trains. including the magazine ol' igniting powder, in a single part separable from the body ot the fuse, and adapted to be easily placed therein in proper relationship to the primer and the boosterY The detonating plug' 2l is simple in construction and easily and cheaplyinanutactui-ed. lt may be easily loaded. and, when loaded. constitutes a'complete article that is furnished to those whoassemblc. and load the t'use. This makes tor safety aswell as cheapness in manufacture. The steeland notched diskl and the detonatn#y plug heretot'ore described-pertain to a delay detonating fuse. By omitting the disk7 perforating the center of the felt washer. and also omitting' the closing plug, the fuse can be ronvertcd 'into a normal quick acting fuse.

T'l-nough the heavy wall fl separatingthe two main chambers of the fuse is formed the channel of detonation between such chambers. The port-ion ofy the channel of detonation entering the chamber for the booster charge is covered by a shield 56 of thin. metal, lcup-shaped to conform to the channel and the bottom of the chamber. lts object is to prevent any of the explosive vfrom the booster charge entering the rpassage in which the oscillating bolt operates. Any other suitable retaining device can 'be employed. For certain booster charges orcertain-kinds ot' loading` the shield or retaining Ydevice may be dispensedwith. lntercepting this channelis an oscillating bolt or turret 29 through which is -a diametric passage 8O that,` when lnought into alignment with the two `parts of the channel of detonation formed in the wall 44, registers therewith and'constitutes part of such chanw nel. The means for automatically operat ing'the bolt 29are fully illustrated and described in my aforesaid application #502,385, and need-not be specitically described herein. Suffice it to say that the bolt under normal-safety conditions is turned to such position that the diametric `passage through it does not register with the channel ot detonation. but .instead the bolt acts to intercept:

this channel and constitutes a barrier betweenthe `chambers SBand 8, so that should any or all of the explosive elements located inthe'chamber 33 prematurely or accidently ignite the forces generated thereby `wouldfbe effectively cut off from the booster charge and would not ignite `the latter. Vhen, however-,the shell is tired 'from a gun the oscillating bolt is automatically operated and moved lfrom its safety position. inten cepting the channel of detonation, and turned so as to bring-the diametric passage throughit into register with the stationary parts of the channel of detonation.

There is also provided within the fuse stock and between the chamber for `the booster charge and that for theftiring mechanism,` etc., an expansion chamber 52. Should there be any explosion ofv the detonator when the oscillating bolt is in its safety position the effect would-bc to cause a flattening out of?theoscillatiimy bolt audfthe escape oi the gascs-trom'the explosion-into the expansion chamber. I

As in case of thehamnjler block or 'tiring plunger, the oscillating bolt does not move into the armed position until a'lter the shell has `leftrthe bore ofthe gun. A premature explosion of the detonator in tiringwould not.therefere.lead to a detonation of the shell .andresulting destruction of the gun.

The oscillating bolt is assembled to the fuse from the exterior and there is a chamber or opening 54 in the side of the fuse stock for the purpose. There is also provided in the side of the fuse a screw hole 55 leading to the expansion chamber 52 and closed by a screw-threaded plug 53. After the oscillating bolt has been assembled to the fuse, or at any time thereafter, it is practical to unscrew the plug 53 and ascertain whether or not the oscillating bolt is in its desired safety position, since the hole 55 is so located as to be directly opposite the end of the diametric opening through the oscillating bolt when the latter is in safety position.

The detonating'fuse herein described and illustrated possesses the very desirable features of being readily loaded and assembled from the exterior and practically in the order of danger of the various component elements. In this design it is practical and desirable, to assemble, as the first operation and from the exterior, the-oscillating barrier bolt, thus intercepting the channel of detonation. The second operation is'to load, from the front end and exterior, the booster charge. The third operation is to assemble the detonator, primer, and firing mechanism elements, from the rear end and also exterior. When such a fuse is assembled with only the oscillating bolt and booster charge, it can be readily transported as a safety explosive, the remaining elements to be assembled at the place where the fuse is required to be used in the loading of shell.

In assembling the' fuse it is the practice, and makes for safety, to remove the plug 53 and inspect the barrier bolt to insure that it is in safety position before the third operation of assembly is performed; and such an inspection, likewise, insures that during handling and transportation the fuse cannot be detonated.

A' fuse such as that described functions as follows: Upon a shell carrying the fuse being fired from a gun the locking plunger pin 38 sets back and frees the firing pin. This, however, remains in safety position so long as the shell is under acceleration, as has been pointed out. In the meantime centrifugal force causes the locking plunger pin 24 to move outwardly, freeing the firing pin from its restraining influence, so that as soon as the shell has left the muzzle of thc gun and acceleration in its flight has ceased.l the firing pin will turn on its pivot and become armed, as has been described. The

oscillating bolt also remains in safety position until after the shell has left the gun, when it also is armed, as has been described. During the flight of the shell the centrifugal force maintains the firing pin in its armed position. Upon impact of the shell against the target the locking bolt 38 moves forward progressively until their inner ends are n reached, Iwhen the flame therefrom, reinforced by that from the magazine of igniting powder, passes thro-ugh the flash passage 28 and ignites the detonator. The waves of detonating force generated by the explosion of the detonator being reflected and directed forwardly by the reflecting walls of the cavity 27 ruptures the shield 36 and pass through the open channel of detonation across a considerable air gap or gaps into the booster charge, firing the latter. The rigid reflecting walls of the booster chamber reflect and direct the waves of detonating force, produced by the detonation of' the booster charge, forwardly into the mass of explosive constituting the bursting chamber of the shell which is thereby detonated.

The capacity of the detonator in this fuse to detonate the booster charge across a considerable air gap constituting the open channel of detonation is its most striking feature. In this particular design the length of the air gap is approximately five times its diameter, and the detonation across such a gap represents an accomplishment not heretofore obtained in the art. The set forward of the shell charge on impact may give rise to a considerable air gap in the rear of the cavity of the shell, and between the fuse and the bursting charge. The fuse is designed so that the detonating waves from the explosive of the booster charge will jump this air gap and detonate the bursting charge.

In this specification and the subsequent claims, the term primer7 refers to the initiator of the explosion of the fuse and may be the ordinary percussion type of primer, the stab type of primer, or, in case of fuses for bombs or other containers for high explosive, any igniting type of primer. The term detonator refers to the usual detonating charge which initiates thc detonation or explosion of the fuse, and is ordinarily of fullninate of mercury, although it may be of other detonating substances used in a similar capacity. The term detonating explosive as used, applies not only to the detonator as herein described, but also to what is commonly known as the booster charge used to detonate larger charges of high explosive. The term high explosive covers such high llO explosive substances as may be lused in a waves'of detonation has beenY employed.

As understoodby writerson the subject of explosives waves of detonationA refer specifically to the waves that' are propagated throughout the massof a high explosive'as' it is being detonated or veryviolently exploded. The velocities of these waves of detonation have beendetermined for various explosives'and' they'are very high, But, in this specification' the term waves of detonation" not only applies to tlie waves of energy that are propagated 'through the mass 'of detonating explosive, but also to the waves of force which my invention has demonstrated act exterior' to and beyond the mass of exi plosive detonated. In the latter case, these waves of 'force have extraordii'iary detonating'capacity, so much so that 'they will detonate another higliexplosive over an a'ir gap the length of which is atleast five times its diameter.

Iv have demonstrated 'that' these waves of detonating force arising` from the detonation of a booster charge having an extreme diameter of one inch willv effectively detonate the bursting charge of a shell over an air gap of six inches. This air gap is 'not enclosedQexcept in so far as the interior wall'of the Ashell may enclose it, and, therefore, in thisvrespect is unlike the enclosed channel of detonating force between the 4detona'tor and the booster charge of the fuse herein described.

In regard to the character of the waves of detonating force which act exterior to the mass of explosive the'y detonation of which gives riseV to them, I find, by reference to Berthelots .Vork on Explosives and rI heir Power, edition of 1892, that this distinguished French authority on. explosives has recognized two kinds or orders of detonating waves. In explaining these detonating waves Berthelot on pages T9 and 8O of his work, used the following language:

Such is the theory which appears to the author to account for explosions byv influence, and for the phenomena which accompanied them.

It rests on the production of' two orders o t waves; the one being the explosive wave, properly so called, developed in the sub.- stance which explodes, and consisting vof a transforn'iation incessantly Vrel'no'd'uce'd from chemical actions into caloritic and mechanical actions, which transmit the's'hock to the supports and contiguous bodies; and the other purely physicalV and mechanical, which also transmits sudden pressures around the center of vibration to neighboring bodies and by' a peculiar circumstance to a fresh mass of explosive matter.

The first order or kind of detonating wave is that which is propagated through the mass of explosive as `it is'b'eing detonated, and is the result of chemical action throughout the explosive. vThe second order or kind, referredto as a purely physical and mechanical detonating wave, constitutes the inf1uence or waves of influence which detonate across air gaps or at a distance.

vThe presence of these waves of influence has been recognized by other writers on explosives, as Marshall and'Brunswig; and whenever one explosive is detonated which is not` in contact with the explosive initiating its detona-tion, the phenomenon is att-ributed to influence.

I-Ieretofore all detonating fuses have had the .several explosive bodies or agencies in close contact with each other at the time of detonation, and the train orchannel of'detonation, where there was one, has always been a` channel filled with explosive, so that the train from the detonator4 to the booster charge and to the bursting'charge' of ythe shell has been one of contact of high explo-y sive substances. But I employ for detonation transmission anopen channel of detonationof considerable length, and across the air gap thus formed' and throughthis ,open

channel of detonation I ain able to successfully detonate the booster charge. Undoubtedly this detonation hasl been accomplished by intluence, or waves of influence, or the physical and mechanical waves referred to by Berthelot,'and which are referred to in the speciication and accompanying claims as waves of detonating4 force. These waves of inliuence have been measured by scientists, and it has vbeen noted that their intensity and velocity fall off from the center or focus of the detonation which gives rise to them, whereas, the first order or kind of det# onating waves are all of practically constant velocity and intensity throughout the mass of the'explosive. liVhile these waves of influence may fall off in intensity and velocity as stated above under ordinary conditions, I have, however, by means described, been able to reflect, direct and concentrate them, and have thus given them greater detonating power than if they were not so controlled, thus more than compensating for the normal falling oit' in their intensity due to distance from their source.

In the early experiments conducted by the Engineer Corps of the Army it was'found that the detonation of one submarineA torpedo would within a certain radius give rise to the detonation of another subn'iarine torpedo; vand it was also found that this iniucnce or these waves 'of influence will act at a greater distance in a Huid medium like water, than they will in air.

The phenomenon of ydetonating the booster. charge by the reflecting and directing of the waves of influence from the detonator as stated in this specification has also been observed in case of the detonation of the booster charge, for in the latter case the waves of influence Will act across a considerable air gap and successfully detonate the bursting charge of the shell.

Ordinarily air is the fluid that fills the open channel of detonation, and by' open channel in the specification and the claims is meant a channel free from explosive. I do not wish, however, that my invention be limited to the use of air as the only fluid medium for transmitting this second order of waves of detonation, or waves of influence, because it is conceivable that other fluids, gaseous and liquid, can be used advantageously.

Throughout the specification and claims where I have employed the words waves of detonating force I have used them synonymously with influence, waves of influence, or the physical and mechanical waves referred to by Berthelot. Andthe discussion in this specification will make it obvious that these waves of influence are quite different from the ordinary or chemical, waves of detonation which depend vupon contact or` intimate association of the explosive elements for their propagation and utilization in detonating fuses. But in case of the detonating fuse herein described, I have utilized influence or waves of influence, in the successful detonation of the fuse and shell which has not heretofore been accomplished, and marks, therefore, a great advance in the art. The operation of the fuse is therefore different from any other in use.

The phenomenon arising from the experimental work conducted by me in the development of the detonating fuse herein described is obviously quite different from any phenomenon exhibited by the behavior of other detonating fuses of which I have any knowledge, for I have been able to lsecure remarkable results with a detonator the mass of which is about one-fifth of that used in other detonating fuses, while the mass of the booster charge is not over one-third of the mass of those generally used in other detonating fuses for similar work.

Many of the features described are applicable to fuses for bombs, torpedoes and other containers of high explosives.

By my invention I secure First A fuse so designed that it is safe in handling and storage against shock and rough usage;

Second. A fuse so designed that when assembled in a shell loaded with high explosive, there cannot be detonation of such shell in storage, handling, or during its flight in the bore of a gun, from any cause peculiar to the fuse;

Third. A fuse so designed that it operates satisfactorily even when the detonator is loaded under a very high degree of coinpression;

Fourth. A fuse so designed that itrequires much less of a detonator and of a booster charge than has been heretofore employed in the art;

Fifth. A fuse so designed that the detonator detonates the booster charge across an air gap approximately fivetimes its diameter, an accomplishment not heretofore obtained in any fuse; and

Sixth. A fuse so designed that it operates satisfactorily in a shell loaded with high explosivewhen an unavoidable air gap occurs due to loading or the setl forward of the explosive in the shell when the latter strikes heavy armor.

What I claim is l. A percussion fuse comprising a fuse body in which is formed a chamber, a hammer block movable in the chamber and adapted to set forward on impact, and an anti-creeping coil spring at the rear of the plunger having its oppositeends attached respectively to the hammer block and the fuse body.

2. A percussion fuse, comprising a fuse body in which is formed a chamber, a hammer block supported in the chamber and free to move forward on impact, and an anticreeping coil spring, the ends of the spring occupying recesses formed respectively in the hammer block and the fuse body, the inner Walls of the recesses being screwthreaded and the spring being screwed into the said recesses and engaging with the threaded walls thereof.

3. In a percussion fuse, a hammer block, a firing pin carried thereby, pivotally supported so as to be free to oscillate, the pin being arranged to be moved to armed position'by centrifugal force during the exterior flight of the shell carrying the fuse, and locking plunger pins for holding the firing pin in safety position, one movable radially and the other longitudinally of the fuse, the former being movable by centrifugal force to release the pin and the latter being mov able and adapted to be set back to release the ring pin at the instant the gun is fired.

4L. In a percussion fuse, a hammer block, a firing pin pivotally supported therein and arranged to normally occupy a safety position, Vthe firing pin having an eccentric Weighted portion, a radially acting lockingpin for the firing pin, a longitudinally acting locking pin for the firing pin, the former being' movable by centrifugal force to release the firing pin and the latter being arranged to be set back to release the firing pin when the gun is fired, the Weighted portion of the firing pin being arranged to be acted upon both by centrifugal force and by inertia, during the time the shell is accelerating during its flight, the arrangement being such that the force of inertia is greater than centrifugal force during the period et the acceleration of the shell in the gun.

5. In a percussion fuse, a hammer block, a iring pin supported therein and arranged to normally occupy a safety position a longitudinally acting locking pin for the firing pin, so arranged as to beset back to release the firing pin when the gun is fired, and means provided for preventing the said locking pin from engaging again with the firing pin until impact.

6. In a high explosive detonating fuse, a plug carrying both a detonator and a delay powder train.

7. In al high explosive detonating fuse, a plug carrying a detonator and a plurality of delay powder trains for igniting the detonator, the latter arranged to be ignited at separate points and to simultaneously burn out.

8. In a high explosive detonatingl fuse, a plug carrying a. detonator, a delay powder train and a magazine of loose igniting powder between the powder train and the det- I onator.

9. In a high explosive detonating fuse, a plug carrying a detonator and a plurality of delay powder trains arranged to be ignited at separate points and leading to a magazine of loose igniting powder adapted to fire the detonator.

10. In a high explosive detonating fuse, the combination with the fuse body, of a single carrier plug separate from the fuse body, in which are located a time train and a. detonator, a primer and means for firing the primer, the primer igniting the time train and the latter firing the detonator.

11. In a high explosive detonating fuse, ther combination with the fuse body, of a single and separate carrier plug in which are loca-ted a plurality of time trains and a `detonator, a primer, and means for iring the primer, the primer being arranged to ignite the several time trains and the latter' being arranged to tire the detonator from a common location.

i detonator, and a single carrier, separate from the fuse body, in which are loaded the time train, magazine of igniting powder and the detonator.

13. In a high explosive d-etonating fuse, the combination 'with the fuse body and a primer and means for firing the primer, oi'

a delay powder train arranged to be ignited by the primer, a magazine otl'oose igniting vance of the primer plug, and a detonator carried by thev said separate plug.

15. Thercombination stated in claim 11i i including also a timetrain ignited by the primer and arranged to ire the det-onator, carried by the said separate plug.

16. In a high explosive detonating fuse, a fuse body in which are formed chambers, one to receive a booster charge and the other to receive the primer and detonator, these chambers being separated by a partition wall through which is a. channel of communication, an automatically operating barrier in the said channelY arranged to intercept the same when the fuse is unarmed, ay plug for the primer having screw-thread engagement with the fuse body, mechanism for firing the primer, and a carrier plug for the detonator and a time train adapted to freely move to its position against the said partition wall separating the chambers of the fuse, such plugv being held in place bythe primer plug when the latter isV screwed into position, and there being; formed in the said carrier plug cavities adapted to receive respectively a time train ignited by the flashfrom the primer and a detonator fired by the time train.

17. In a high explosive detonating fuse,`

munication, an "automatically operating barrier in the said channel arranged to intercept the same when; the fuse is unarmed, a plug n for the primer having screw-thread engagement with the fuse body, mechanism for tiring the primer, and a plug carrying a detonator and delay powder trains, thecarrier plug being; adapted to free-ly move. to its position against the partition wall sep.- arating the chambers of the fuse, and being held in place by the primer plug when the; latter is screwedv into position, the detonator and delay powder trains occupying, respectively, cavities in the carrier plug, and. the powder tra-ins being arranged to be simultaneously ignited by the Hash from the primer and to simultaneously burn out and deliver their flames in a common locality to ignite the detonator.

18. The combination stated in claim 17 inl,cluding also a magazine of igniting powder in its other end channels to receive the time trains, the cavity and channels communicating, and the channels for the time trainsV opening into a flash passage leading fromr the primer, and means for securely holding in position within the fuse the said carrierr plug.

20, In a percussion fuse, a chambered fuse body, a plug carrying a primer having screw-thread connection with the wall oi. the fuse chamber, mechanism for firing the` Vprimer located withinthe said chamber, a carrier plug for a time train also located in the chamber, and a disk of yielding nat 1-re interposed between the primer plug and the said carrier for the time train arranged to' operate as a seal for the time train except the end thereof which is intended to be ignited by the flash from the primer.

2l. In a high explosive detonating fuse, a chambered fuse body, a plug carrying a primer having screw-thread connection with the wall of the fuse chamber, mechanism for firing the primer located within the said chamber, a carrier plug for both a detonator and time trains, freely movable within the chamber and arranged to be held securely inplace by the primer plug, and a disk of. yielding nature interposed between the primer plug and the carrier plug and armraiiged to operate asa seal forthe time 'trainsf xcptthe ends thereof which it is intended' shouldbeifgnitedby the flash from the primer QQ :a high explosive", deton'atingv Afuse,

e maar "15mg" having 'ffiaea in one-ena@ 'masa ana-'laghi maar a carrier" plugfhavin '01 formey cavity lior'rla'deitohator, hav' teiioij 'cavity for IfiagazineK of" ignitiri priwd"er,filtri/iiig `a prlurafl'it delay1powdetrairsjlea central" cavity`"`t th" anddhaving an ,ope

of* ra t.rigid carrier; having wfc'lth; communicating i chere@ and .mme fel: fi so tha of;

" wal saidlopen VV clianlnel the plug opposite that in which is formed the detonator cavity through which the interior central cavity may be loaded with igniting powder, and a tightly tting plug for closing the said opening.

24. A fuse formed with a threaded channel into which is loaded and compressed a delay powder train.

:25. A fuse, provided with two primers arranged in series, and means for successively firing the said primers. Y

26. A fuse having a single firing pinarH ranged Yto function on impact and twoY primers arranged in series, both adapted to be ignited by the firing pin, the primer nearest the firing pin -being of the stab type, and the other of the percussion type.

27. In a detonating fuse, the combination of a rigid carrier having an open Yended cavity, the wall of which liares toward the front and converges toward the rear, a detonating charge loaded in the said cavity, a charge orn high explosive a channel of detonation between the detonator and the charge of high explosive, and means for firing the detonating charge, Athe recited features being so arranged that on firing the detonating charge the resulting waves of detonating torce are reflected from the wall or" the cavity in which it is located, and directed vforwardly and through the said channel of detonation, and caused to directly act upon and detonate the high explosive charge.

28. In a detonating fuse, the combination of a rigid carrier having a cavity flaring outward towards the front and convergingv to and closed at the rear except for a fifingl passage, a detonating charge loaded in said cavity, a charge of high explosive, and a channel free from explosive, of greater length than its width, between the said detonating and high explosive charges, so that on the firing o'l' the detonating charge,the resulting waves of detonating force reilected fromgthe, wall olf the said cavity pass iijo'ughsaidppen channel and effec- Onward' iw'aidsthe .fi-but; andere@ ,the :i said, high explosivel to and closed at" @balear-except "fra; ring assafre a detonatin' charfrel loaded'in said pared with the ivitlth ofthe 's 'aid Acavity andk comii'iunicating 'Withf said detonating charge,

and means for iiringtlie latter so thaton its explosionx the Waves of A detonatin'g' force are reflected Vthrough"said open andl contracted' channel.

In'a detonatingifuse, the combination of a rigidr carrier 'having' an open ended cavity of substantially parabolic curvature, a detonator loaded' insa'itl cavity, a tiring passage at the rear thereof, so that on the explosion ot the detonator the resulting Waves of detonating torce are reiected from the Wall of said cavity and pass out through the open end thereof and a shield closing the opening of the said tiring passage into the detonator cavity.

33. In a detonating use, the combination of a rigid carrier having'an open ended cavity of substantially parabolic curvature, a detonating charge loaded in said cavity, a metal shield, thicker at the middle than at the edges, closing the open end of said cavity, and means for tiring the said detonating charge, so that the Waves of detonating force Will be reflected from the Wall of the said cavity and pass through and be re- :t'racted as desired by the said shield.

34. In a detonating fuse, the combination ot a booster charge, a detonator exterior thereto and loaded in a cavity the rigid wall of which reflects and directs the Waves of detonating force resulting from the explosion of said detonator so that they Will act etfectively across a considerable air gap, means for tiring the detonator, a channel ot' dctonation Jfree Jfrom explosive connecting said booster charge and detonator, a barrier intercepting said channel when the fuse is in safety position and capable of being automatically moved into armed position malring the channel of detonation continuous, so that on the explosion of the detonator the resulting Waves of detonating torce pass through the length of the said channel and detonate the booster charge.

35. In a fuse, a highly compressed detonator loaded in aI cavity the interior of which ares outward to the front and converges to the rear, the Wall enclosing the cavity being thick and rigid, the rear of the rdetonator in which is formed a: cai

cavity havingan ignitin'g passage' foref- 'ectively explodingthe detonator' in` said cavity.

3G. In a tuse, a separable carrier for a y' .y tiaring towardl the" front and converging 'tof Ward the 'rear yand vvithan ignition opening in its rear portion, the wall of the carrier surrounding the y cavitynbeing thick` and rigid, a chargeof a highly compressed detonator' in the said cavity, .and vmeans vfor tiring the detonator at the said ignition opening. y

In a detonatingi fuse, a fuse stock having a chamber for theboo'ster cl1arge,'a second chamber 'for an intercepting barrier,- and a third chamberfor the tiring mechanism, andl primer elements, all said chambersv being so designed 'and' arrangedv that' the booster charge is loaded from the front, the barrier' assembled fromtheside, andfthe tiring vmechanism, primer and detonating elements assembled from the rear, and each independently ot the others.

38. In a detonating fuse, the combination of a fuse stock having a channel of detonation, a barrier adapted to intercept such channel, an expansion chamber in proximity to the barrier, and a detonator at the rear end of the channel of detonation, all. so designed and arranged that in the event of the premature explosion of the detonator, the barrier would be deformed, permitting the resulting explosive gases to be diverted into the expansion chamber.

39. In a detonating fuse, the combination of a fuse stock having a channel of detonation, a barrier adapted to register with and to intercept said channel, an expansion chamber in proximity to the barrier, the channel of detonation being exposed to the exterior through an opening in the fuse stock, and a screw plug for closing said opening, and all so designed and arranged that on removing the said screw plug the position of the barrier with reference lto the channel of detonation may be observed and inspected.

40. In a detonating fuse, a fuse stock formed with chambers in one of which is a booster'charge and in the other a detonator, there being a channel of detonation between such chambers, a movable barrier arranged to'intercept the said channel when in one position and to open it when in another, there being formed in the fuse stock an expansion chamber open to the exterior and in proximity to the barrier, to receive the explosive gases should the detonator prema turely explode, when the channel of detonation is closed by the barrier, the opening to such chamber being located to permit inspection of the barrier from the outside7 and a plug for closing the opening.

4l. In a detonating nse, the combination of a booster charge, a detonator exterior thereto and loaded in a cavity the rigid Wall of which directs t-he Waves of detonatng force resulting from the explosion of said detonator so that they will act effectively across a considerable air gap, means for tiring the detonator, a channel of detonation :free from explosive connecting said booster Charge and detonator, a barrier intercepting said channel when the fuse is in safety position and capable of being auto matically moved into armed position malting the channel of detonation continuous, so that on the explosion of the detonator the resulting Waves or" detonating force pass through the length of the said Channel and detonate the booster charge.

42. In a detonating fuse, the combination of a detonator loaded into a cavity the rigid Wall of which reflects and concentrates the Waves rof detonating force resulting from the explosion of said detonator so that they will act ell'ectively across a Considerable aiigap, means for firing the detonator, a channel of detonation free from explosive leading from the said detonator, and a barrier intercepting the said channel When the fuse is in safety position andv capable of being automatically moved into armed position, making the channel of detonation Continuous, lso that on the explosion of the detonator the resulting Waves of detonating force n moved automatically to arm the fuse, making the channel of detonation continuous, so that on the explosion of the detonator the resulting Waves of detonating force pass through the entire length of the said detoy nating channel and detonate the booster.

CHARLES P. WATSON. 

